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MIPS: Remove unused R6000 support

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The kernel contains a small amount of incomplete code aimed at
supporting old R6000 CPUs. This is:

  - Unused, as no machine selects CONFIG_SYS_HAS_CPU_R6000.

  - Broken, since there are glaring errors such as r6000_fpu.S moving
    the FCSR register to t1, then ignoring it & instead saving t0 into
    struct sigcontext...

  - A maintenance headache, since it's code that nobody can test which
    nevertheless imposes constraints on code which it shares with other
    machines.

Remove this incomplete & broken R6000 CPU support in order to clean up
and in preparation for changes which will no longer need to consider
dragging the pretense of R6000 support along with them.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16236/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Paul Burton 2017-06-05 11:21:27 -07:00 committed by Ralf Baechle
parent 114c370845
commit 3b2db173f0
10 changed files with 3 additions and 165 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
arch/mips/Kconfig
View file

@ -1627,14 +1627,6 @@ config CPU_R5500
NEC VR5500 and VR5500A series processors implement 64-bit MIPS IV
instruction set.
config CPU_R6000
bool "R6000"
depends on SYS_HAS_CPU_R6000
select CPU_SUPPORTS_32BIT_KERNEL
help
MIPS Technologies R6000 and R6000A series processors. Note these
processors are extremely rare and the support for them is incomplete.
config CPU_NEVADA
bool "RM52xx"
depends on SYS_HAS_CPU_NEVADA
@ -1950,9 +1942,6 @@ config SYS_HAS_CPU_R5432
config SYS_HAS_CPU_R5500
bool
config SYS_HAS_CPU_R6000
bool
config SYS_HAS_CPU_NEVADA
bool
@ -2180,7 +2169,7 @@ config PAGE_SIZE_32KB
config PAGE_SIZE_64KB
bool "64kB"
depends on !CPU_R3000 && !CPU_TX39XX && !CPU_R6000
depends on !CPU_R3000 && !CPU_TX39XX
help
Using 64kB page size will result in higher performance kernel at
the price of higher memory consumption. This option is available on
@ -2248,11 +2237,11 @@ config CPU_HAS_PREFETCH
config CPU_GENERIC_DUMP_TLB
bool
default y if !(CPU_R3000 || CPU_R6000 || CPU_R8000 || CPU_TX39XX)
default y if !(CPU_R3000 || CPU_R8000 || CPU_TX39XX)
config CPU_R4K_FPU
bool
default y if !(CPU_R3000 || CPU_R6000 || CPU_TX39XX || CPU_CAVIUM_OCTEON)
default y if !(CPU_R3000 || CPU_TX39XX || CPU_CAVIUM_OCTEON)
config CPU_R4K_CACHE_TLB
bool

1
arch/mips/Makefile
View file

@ -151,7 +151,6 @@ cflags-y += -fno-stack-check
#
cflags-$(CONFIG_CPU_R3000) += -march=r3000
cflags-$(CONFIG_CPU_TX39XX) += -march=r3900
cflags-$(CONFIG_CPU_R6000) += -march=r6000 -Wa,--trap
cflags-$(CONFIG_CPU_R4300) += -march=r4300 -Wa,--trap
cflags-$(CONFIG_CPU_VR41XX) += -march=r4100 -Wa,--trap
cflags-$(CONFIG_CPU_R4X00) += -march=r4600 -Wa,--trap

5
arch/mips/include/asm/cpu-type.h
View file

@ -151,11 +151,6 @@ static inline int __pure __get_cpu_type(const int cpu_type)
case CPU_R5500:
#endif
#ifdef CONFIG_SYS_HAS_CPU_R6000
case CPU_R6000:
case CPU_R6000A:
#endif
#ifdef CONFIG_SYS_HAS_CPU_NEVADA
case CPU_NEVADA:
#endif

5
arch/mips/include/asm/cpu.h
View file

@ -285,11 +285,6 @@ enum cpu_type_enum {
CPU_R2000, CPU_R3000, CPU_R3000A, CPU_R3041, CPU_R3051, CPU_R3052,
CPU_R3081, CPU_R3081E,
/*
* R6000 class processors
*/
CPU_R6000, CPU_R6000A,
/*
* R4000 class processors
*/

2
arch/mips/include/asm/module.h
View file

@ -114,8 +114,6 @@ search_module_dbetables(unsigned long addr)
#define MODULE_PROC_FAMILY "R5432 "
#elif defined CONFIG_CPU_R5500
#define MODULE_PROC_FAMILY "R5500 "
#elif defined CONFIG_CPU_R6000
#define MODULE_PROC_FAMILY "R6000 "
#elif defined CONFIG_CPU_NEVADA
#define MODULE_PROC_FAMILY "NEVADA "
#elif defined CONFIG_CPU_R8000

1
arch/mips/kernel/Makefile
View file

@ -37,7 +37,6 @@ obj-$(CONFIG_FUNCTION_TRACER) += mcount.o ftrace.o
obj-$(CONFIG_CPU_R4K_FPU) += r4k_fpu.o r4k_switch.o
obj-$(CONFIG_CPU_R3000) += r2300_fpu.o r2300_switch.o
obj-$(CONFIG_CPU_R6000) += r6000_fpu.o r4k_switch.o
obj-$(CONFIG_CPU_TX39XX) += r2300_fpu.o r2300_switch.o
obj-$(CONFIG_CPU_CAVIUM_OCTEON) += r4k_fpu.o octeon_switch.o

18
arch/mips/kernel/cpu-probe.c
View file

@ -1394,24 +1394,6 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
MIPS_CPU_DIVEC | MIPS_CPU_LLSC;
c->tlbsize = 48;
break;
case PRID_IMP_R6000:
c->cputype = CPU_R6000;
__cpu_name[cpu] = "R6000";
set_isa(c, MIPS_CPU_ISA_II);
c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
MIPS_CPU_LLSC;
c->tlbsize = 32;
break;
case PRID_IMP_R6000A:
c->cputype = CPU_R6000A;
__cpu_name[cpu] = "R6000A";
set_isa(c, MIPS_CPU_ISA_II);
c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS;
c->options = MIPS_CPU_TLB | MIPS_CPU_FPU |
MIPS_CPU_LLSC;
c->tlbsize = 32;
break;
case PRID_IMP_RM7000:
c->cputype = CPU_RM7000;
__cpu_name[cpu] = "RM7000";

99
arch/mips/kernel/r6000_fpu.S
View file

@ -1,99 +0,0 @@
/*
* r6000_fpu.S: Save/restore floating point context for signal handlers.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996 by Ralf Baechle
*
* Multi-arch abstraction and asm macros for easier reading:
* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
*/
#include <asm/asm.h>
#include <asm/fpregdef.h>
#include <asm/mipsregs.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>
.set noreorder
.set mips2
.set push
SET_HARDFLOAT
/**
* _save_fp_context() - save FP context from the FPU
* @a0 - pointer to fpregs field of sigcontext
* @a1 - pointer to fpc_csr field of sigcontext
*
* Save FP context, including the 32 FP data registers and the FP
* control & status register, from the FPU to signal context.
*/
LEAF(_save_fp_context)
mfc0 t0,CP0_STATUS
sll t0,t0,2
bgez t0,1f
nop
cfc1 t1,fcr31
/* Store the 16 double precision registers */
sdc1 $f0,0(a0)
sdc1 $f2,16(a0)
sdc1 $f4,32(a0)
sdc1 $f6,48(a0)
sdc1 $f8,64(a0)
sdc1 $f10,80(a0)
sdc1 $f12,96(a0)
sdc1 $f14,112(a0)
sdc1 $f16,128(a0)
sdc1 $f18,144(a0)
sdc1 $f20,160(a0)
sdc1 $f22,176(a0)
sdc1 $f24,192(a0)
sdc1 $f26,208(a0)
sdc1 $f28,224(a0)
sdc1 $f30,240(a0)
jr ra
sw t0,(a1)
1: jr ra
nop
END(_save_fp_context)
/**
* _restore_fp_context() - restore FP context to the FPU
* @a0 - pointer to fpregs field of sigcontext
* @a1 - pointer to fpc_csr field of sigcontext
*
* Restore FP context, including the 32 FP data registers and the FP
* control & status register, from signal context to the FPU.
*/
LEAF(_restore_fp_context)
mfc0 t0,CP0_STATUS
sll t0,t0,2
bgez t0,1f
lw t0,(a1)
/* Restore the 16 double precision registers */
ldc1 $f0,0(a0)
ldc1 $f2,16(a0)
ldc1 $f4,32(a0)
ldc1 $f6,48(a0)
ldc1 $f8,64(a0)
ldc1 $f10,80(a0)
ldc1 $f12,96(a0)
ldc1 $f14,112(a0)
ldc1 $f16,128(a0)
ldc1 $f18,144(a0)
ldc1 $f20,160(a0)
ldc1 $f22,176(a0)
ldc1 $f24,192(a0)
ldc1 $f26,208(a0)
ldc1 $f28,224(a0)
ldc1 $f30,240(a0)
jr ra
ctc1 t0,fcr31
1: jr ra
nop
END(_restore_fp_context)
.set pop /* SET_HARDFLOAT */

15
arch/mips/kernel/traps.c
View file

@ -2428,21 +2428,6 @@ void __init trap_init(void)
set_except_vector(EXCCODE_TR, handle_tr);
set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
if (current_cpu_type() == CPU_R6000 ||
current_cpu_type() == CPU_R6000A) {
/*
* The R6000 is the only R-series CPU that features a machine
* check exception (similar to the R4000 cache error) and
* unaligned ldc1/sdc1 exception. The handlers have not been
* written yet. Well, anyway there is no R6000 machine on the
* current list of targets for Linux/MIPS.
* (Duh, crap, there is someone with a triple R6k machine)
*/
//set_except_vector(14, handle_mc);
//set_except_vector(15, handle_ndc);
}
if (board_nmi_handler_setup)
board_nmi_handler_setup();

5
arch/mips/mm/tlbex.c
View file

@ -2634,11 +2634,6 @@ void build_tlb_refill_handler(void)
#endif
break;
case CPU_R6000:
case CPU_R6000A:
panic("No R6000 TLB refill handler yet");
break;
case CPU_R8000:
panic("No R8000 TLB refill handler yet");
break;